*{
    margin: 0;
    padding: 0;
    text-decoration: none;
}

body{
    background-image: url("../../pic/bg.jpg");
}

body div{
    margin: 8px auto;
}

header{
    width: 960px;
    height: 100px;
    margin: 0 auto;
    background-color: black;
    border-radius: 0 0 20px 20px;
    opacity : 0.8;
}


div.f_l1{
    width: 960px;
    margin: 0 auto;
    overflow: hidden;
}

article,nav{
    float: left;
    margin: 5px;  
    overflow: hidden;
}

article{
    width: 777px;
}

div.l1_right{
    width: 160px;
}